Message8922

We need to throw an appropriate Python error to complete this fix, given that we cannot support such lone surrogates using Jython's underlying UTF-16 representation of Unicode. I suggest ValueError, following this model:

>>> unichr(-1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: unichr() arg not in range(0x110000)

So maybe the text should be somewhat like the following:

ValueError: unichr() arg is a lone surrogate in range (0xD800, 0xDFFF) (Jython UTF-16 encoding)

Target beta 4